1. Field of the Invention
This invention is in the general field of ore milling and is more particularly directed to an impact classification mill wherein the ore is disintegrated by impact between the ore and an impact rotor unit. In the removal of desirable minerals from waste materials in a given ore it is frequently necessary to reduce the raw size of the ore chunks by a multistep reduction process. Furthermore it is frequently necessary to obtain a relatively uniform final particle size for a various concentration whereby the desirable materials are separated. The processes associated with the crushing, milling, discharge, and classification of ore require much labor, resulting in the expenses associated with supporting a substantial labor force at the location of the ore deposit. Also, each of the processes is relatively power intensive resulting in a high power expenditure. Furthermore, for each step in the process the abrasive and impacting forces associated with the reduction of the ore produces a high wear condition, resulting in considerable down time for the machinery, and the expensive replacement parts.
2. Description of the Prior Art
There have been a number of various types of mills available in the past for the use in reduction or ore. Such mills have been in use in the past are primarily directed to crushing and the like, without the reference to up-grading of the mineral classifying function.
Because of the deficiencies of prior art reduction processes various approaches have been proposed, whereby the process of crushing, milling, and classification can be accomplished in a single machine. However, previous prior art devices have failed to provide for sufficient reducing force in conjunction with a device that provides adequate control over the finally reduced product, so that a uniform classified size may be consistently produced. One of the great deficiencies has been a tendency of material to pack in the bottom of the impact reduction chamber. This has been cured in the present invention by the use of a "fluidizer." It is therefore desirable to have an ore reduction mill which combines the functions of crushing, milling and classification in a single housing and with a single drive motor. Such a mill is particularly desirable if the wearing parts of the mechanism are inexpensive, and easily replaced, and if positive control over the final particle size is available.